Many internal combustion engines include turbochargers, or superchargers configured to force more air mass into an engine's intake manifold and combustion chamber by compressing intake air with a compressor driven by a turbine disposed to capture energy from the flow of the engine exhaust gas. However, compression tends to heat the intake air, leading to a reduction of the density of the charge air. It is known to use a charge air cooler to compensate for heating caused by supercharging.
In order to achieve high Charge Air Cooler (CAC) efficiency in boosted applications and under hot ambient operating conditions, charge air coolers should be large and receive “First Air”, (e.g., be in front of a radiator and all other cooling devices). During operation in humid and cooler climates, the size of the CAC may be such that water vapor in the air will condense out and be stored in the CAC. When the flow of intake air reaches a high enough velocity, condensed water may be stripped out of the CAC and ingested into the engine. However, if too much water is ingested into the engine too rapidly, the engine may misfire. Such misfiring can be extreme. Conversely, air flow velocities during low air flow demand remain high and may not allow for condensation build up in the CAC.
Embodiments may provide a valve which may be actuated in boosted engine applications. The valve may be either mechanical or electrical, and in some examples may be located in the charge air cooler (CAC), the inlet tank, or the outlet tank to utilize the required volume of the CAC as needed for predetermined engine operating conditions.
Embodiments may utilize one or more valves configured to close off portions of the CAC during low engine air flow requirements and open the entire CAC during high engine air flow requirements. In this way, efficiency requirements may be better met during both low air flow operation and high air flow operation.
A charge air cooler arrangement, a charge air cooler tank, and method are disclosed. The charge air cooler arrangement includes a charge air cooler having an operable thermal transfer area configured to transfer heat from inside the charge air cooler to outside of the charge air cooler. The charge air cooler arrangement may also include a valve configured to change the operable thermal transfer area from a relatively large area to a relatively small area and back again. In this way the amount of thermal transfer area, and the volume of the CAC, may be adjusted according to engine operation. For example, during operating conditions more prone to condensate formation (e.g., lower flow engine operating conditions), the valve can be adjusted to reduce the number of open channels in the charge air cooler, thereby increasing air flow velocity. However, during operating conditions less prone to condensate formation (e.g., higher flow engine operating conditions, as compared to the lower air flow conditions), the valve can be adjusted to increase the number of open channels in the charge air cooler, thereby decreasing air flow resistance and increasing air flow cooling.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.
FIGS. 2-9 are drawn approximately to scale, although other relative dimensions and positioning may be used, if desired.